On the real MCAT the questions will be presented in the sequential format--being 2 passages then a few non-passage based questions and so on. The AAMC presents the passages in this matter from I->VII not to say VII is any harder or easier than I and random order is just what the name implies-- sometimes you get IV or a non-passage based questions first, sometimes last, you never know. The random function is somewhat pointless and for practice sake you should do these tests in the standard setting of timed, sequential and not in any ascending or descending order of difficulty (which you could add).
